Are there any theories to this? Or well is it even true?
Not an expert but from what I understand there are no mentions of wands in the Bible.
Not necessarily the earliest images, but among them. I wrote a lengthy response on magic wands at r/AcademicBiblical here: https://www.reddit.com/r/AcademicBiblical/comments/4yhz1j/z/d6nx5md
Let me know if you have questions.